Wrapping xAOD::TruthParticle barcode calls in Tracking and Trigger code

Follows !71935 (merged), !72085 (merged), !71975 (merged), !72092 (merged), !72097 (merged) and !72114 (merged). Just using HepMC::barcode helper function here as there are some comparisons against unmigrated classes, which we would want to handle carefully when xAOD::TruthParticle::barcode() is dropped in !67195 (closed).